use qip::inverter::Invertable;
use qip::prelude::*;
#[cfg(feature = "macros")]
use qip_macros::*;
use std::num::NonZeroUsize;

#[cfg(feature = "macros")]
#[invert(gamma_inv)]
fn gamma<B>(
    b: &mut B,
    ra: B::Register,
    rb: B::Register,
) -> CircuitResult<(B::Register, B::Register)>
where
    B: AdvancedCircuitBuilder<f64> + Invertable<SimilarBuilder = B>,
{
    let (ra, rb) = b.toffoli(ra, rb)?;
    let (rb, ra) = b.toffoli(rb, ra)?;
    Ok((ra, rb))
}

#[cfg(feature = "macros")]
fn main() -> CircuitResult<()> {
    let n = NonZeroUsize::new(3).unwrap();
    let mut b = LocalBuilder::default();
    let ra = b.register(n);
    let rb = b.register(n);

    let (ra, rb) = program!(&mut b; ra, rb;
        gamma ra[0..2], ra[2];
        gamma_inv ra[0..2], ra[2];
    )?;
    let _r = b.merge_two_registers(ra, rb);

    Ok(())
}

#[cfg(not(feature = "macros"))]
fn main() {
    panic!("Macros not enabled.")
}